Question

Why does aqueous $Fe(III)$ ion develop intense red colour when it reacts with $SC{N}^{-}$ion while $Fe(II)$ ion does not?

• A. Fe(III) ion forms a charge transfer complex with $SC{N}^{-}$ions
• B. $Fe(III)$ is reduced to $Fe(I)$ which is deep red in colour
• C. $SC{N}^{-}$ion is oxidized to $C{N}^{-}$which forms red coloured complex with $Fe$ (III) ion
• D. $SC{N}^{-}$does not form any complex with $Fe$ (III) ion

Answer 1

Answer: (A)

Correct answer is (a) Fe(III) ion forms a charge transfer complex with $SC{N}^{-}$ions